Replacing a QFP on a 3D printer's mainboard, a technician aligns the new chip and reaches for the iron to set the first tack — orientation checked against the silkscreen dot, and they remember the old chip's rotation anyway. What does the section's ritual require before that tack?

Select one answer.

• Nothing further — the silkscreen is the board's own authoritative mark, and memory of the removal corroborates it.
• A continuity pre-check — with the package aligned but untacked, supply pins are beeped against the board's rails, which catches a rotation electrically before any solder commits it, and which the section prefers over visual witnesses because meters do not misremember: a thirty-second check that makes the marking ritual redundant on any board whose rails are documented.
• The third witness: the ritual is package mark, board silkscreen, AND the before-photo taken at removal — three sources agreeing, checked every time including when it feels unnecessary, because silkscreens get crowded, packages get remarked, memory is not a witness, and the rotation that slips past two checks is exactly the one the third exists to catch.
• A dry-fit power test — the package held in firm contact by a probe while power is applied briefly, proving orientation before solder.